Conventional dishwashers have a number of washing and rinsing phases and a final drying phase. During a typical washing or rinsing phase, a pump forces washing or rinsing liquid upwardly through a conduit and into a rotating spray arm assembly. The washing liquid is distributed from the spray arm assembly by means of orifices or jets spaced along the radially extending arms of the assembly. The spray arms are reactively driven by having at least one of the orifices disposed to discharge a jet stream in a direction such that the spray arm reacts to the force of the discharge and rotates in a horizontal plane.
During a typical washing or rinsing phase, approximately 28-30 gallons of water per minute is pumped through the conduit assembly to the spray-arm assemblies. A relatively large amount of this flow (between 4-6 gallons) leaks through the seal at the joint between the stationary and moving portions of the conduit and the spray arm assembly. This water leakage is detrimental to the performance and reliability of the dishwasher and results in increased energy usage. In addition, as water leaks through the conduit and spray arm assembly, food particles carried by the water flow get lodged between the stationary and moving surfaces causing a reduced spray arm rotational speed that in turn reduces the overall washing performance of the dishwasher and possibly causes deterioration of the assembly.
Therefore, a need exists in the industry for a spray-arm joint assembly that lowers water leakage during washing or rinsing phases and addresses the problem of trapped particles causing deterioration of machine performance or component wear.